透明窗體

透明窗體：
主要代碼：
// TestDlg.cpp : implementation file
//

#include "stdafx.h"
#include "Test.h"
#include "TestDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About

class CAboutDlg : public CDialog
{
public:
	CAboutDlg();

// Dialog Data
	//{{AFX_DATA(CAboutDlg)
	enum { IDD = IDD_ABOUTBOX };
	//}}AFX_DATA

	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CAboutDlg)
	protected:
	virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
	//}}AFX_VIRTUAL

// Implementation
protected:
	//{{AFX_MSG(CAboutDlg)
	//}}AFX_MSG
	DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
	//{{AFX_DATA_INIT(CAboutDlg)
	//}}AFX_DATA_INIT
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CAboutDlg)
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
	//{{AFX_MSG_MAP(CAboutDlg)
		// No message handlers
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CTestDlg dialog

CTestDlg::CTestDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CTestDlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CTestDlg)
		// NOTE: the ClassWizard will add member initialization here
	//}}AFX_DATA_INIT
	// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CTestDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CTestDlg)
		// NOTE: the ClassWizard will add DDX and DDV calls here
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CTestDlg, CDialog)
	//{{AFX_MSG_MAP(CTestDlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_WM_MOVE()
	ON_WM_CREATE()
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CTestDlg message handlers

BOOL CTestDlg::OnInitDialog()
{
	CDialog::OnInitDialog();
	// Add "About..." menu item to system menu.
	// IDM_ABOUTBOX must be in the system command range.
	ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
	ASSERT(IDM_ABOUTBOX < 0xF000);

	CMenu* pSysMenu = GetSystemMenu(FALSE);
	if (pSysMenu != NULL)
	{
		CString strAboutMenu;
		strAboutMenu.LoadString(IDS_ABOUTBOX);
		if (!strAboutMenu.IsEmpty())
		{
			pSysMenu->AppendMenu(MF_SEPARATOR);
			pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
		}
	}

	// Set the icon for this dialog.  The framework does this automatically
	//  when the application's main window is not a dialog
	SetIcon(m_hIcon, TRUE);			// Set big icon
	SetIcon(m_hIcon, FALSE);		// Set small icon
	
	// TODO: Add extra initialization here
	//初始化GDI+.
	m_Blend.BlendOp=0; //theonlyBlendOpdefinedinWindows2000
	m_Blend.BlendFlags=0; //nothingelseisspecial...
	m_Blend.AlphaFormat=1; //...
	m_Blend.SourceConstantAlpha=255;//AC_SRC_ALPHA

	//窗體樣式爲0x80000爲層級窗體
	DWORD dwExStyle=GetWindowLong(m_hWnd,GWL_EXSTYLE);
	SetWindowLong(m_hWnd,GWL_EXSTYLE,dwExStyle^0x80000);
	
	//繪製內存位圖
	HDC hdcTemp=GetDC()->m_hDC;
	m_hdcMemory=CreateCompatibleDC(hdcTemp);
	HBITMAP hBitMap=CreateCompatibleBitmap(hdcTemp,500,500);
	SelectObject(m_hdcMemory,hBitMap);
	
	//使用GDI+載入PNG圖片
	HDC hdcScreen=::GetDC (m_hWnd);
	RECT rct;
	GetWindowRect(&rct);
	POINT ptWinPos={rct.left,rct.top};
	Graphics graph(m_hdcMemory);			//GDI+中的類
	Image image(L"bk.png",TRUE);			//GDI+中的類
	graph.DrawImage(&image,0,0,267,154);	//後面兩個參數要設置成跟圖片一樣大小，否則會失真

	//使用UpdateLayerWindow進行窗口透明處理
	HMODULE hFuncInst=LoadLibrary("User32.DLL");
	typedef BOOL (WINAPI *MYFUNC)(HWND,HDC,POINT*,SIZE*,HDC,POINT*,COLORREF,BLENDFUNCTION*,DWORD);          
	MYFUNC UpdateLayeredWindow;
	UpdateLayeredWindow=(MYFUNC)GetProcAddress(hFuncInst,"UpdateLayeredWindow");
	SIZE sizeWindow={267,154};
	POINT ptSrc={0,0};
	UpdateLayeredWindow( m_hWnd,hdcScreen,&ptWinPos,&sizeWindow,m_hdcMemory,&ptSrc,0,&m_Blend,2);

	return TRUE;  // return TRUE  unless you set the focus to a control
}

void CTestDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
	if ((nID & 0xFFF0) == IDM_ABOUTBOX)
	{
		CAboutDlg dlgAbout;
		dlgAbout.DoModal();
	}
	else
	{
		CDialog::OnSysCommand(nID, lParam);
	}
}

// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.

void CTestDlg::OnPaint() 
{
	if (IsIconic())
	{
		CPaintDC dc(this); // device context for painting

		SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);

		// Center icon in client rectangle
		int cxIcon = GetSystemMetrics(SM_CXICON);
		int cyIcon = GetSystemMetrics(SM_CYICON);
		CRect rect;
		GetClientRect(&rect);
		int x = (rect.Width() - cxIcon + 1) / 2;
		int y = (rect.Height() - cyIcon + 1) / 2;

		// Draw the icon
		dc.DrawIcon(x, y, m_hIcon);
	}
	else
	{
		CDialog::OnPaint();
	}
}

// The system calls this to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CTestDlg::OnQueryDragIcon()
{
	return (HCURSOR) m_hIcon;
}

void CTestDlg::OnMove(int x, int y) 
{
	CDialog::OnMove(x, y);
	// TODO: Add your message handler code here
	CRect rcWindow;                  // 使用MoveWindow函數的示例
	GetWindowRect(rcWindow);
	rcWindow.bottom-=10;
	rcWindow.left+=10;
	rcWindow.right-=10;
	rcWindow.top+=20;
	pChildWnd->MoveWindow(&rcWindow);
}

int CTestDlg::OnCreate(LPCREATESTRUCT lpCreateStruct) 
{
	if (CDialog::OnCreate(lpCreateStruct) == -1)
		return -1;
	
	// TODO: Add your specialized creation code here
	//創建子窗體
	pChildWnd=new COnWindow(this);
	pChildWnd->Create(IDD_ONWINDOW_DIALOG);
	pChildWnd->ShowWindow(SW_SHOW);

	return 0;
}
效果圖：